It probably has to do with 1)The lack of diversity in the jungle, and 2) Jungle is probably the worst position to be in right now. (Unless you are mid against zed.)
As for support, consider this. When is the last time you got any respect for being a support and didn't have to put up with shit from everyone on your team, mainly the adc you have been protecting? I rarely see supports get any respect for doing their job which isn't exactly fun when most adc's are usually cocky and narcissistic.
Neither position is exactly fun. Currently in the jungle, from my experience, if you aren't Jarvan, lee or rek'sai, you aren't gonna have a fun time.